You can't just come here and ask somebody to make an entire map for you without some form of compensation. I can't speak for myself but I'd wager that the people who have the talent to make the kind of map you want have better things to do with their time. If you seriously want somebody to make a map for you, you should be specific about what you want and what the mapper will get from it.

If you want help making a map, go check out hammer tutorials on youtube. Getting started can be pretty complicated and time-consuming and stuff like HHH isn't beginner-level. If you want someone to do it for you, then you'll need to compensate them.

Consider reading this tutorial, implementing arena logic from the ABS Gametype library, and forcing melee using a trigger brush trigger_add_tf_player_condition and setting the condition to 41, cannot switch from melee. Alternately make the map medieval mode by adding a tf_logic_medieval entity anywhere in the map which has roughly the same effect.